Abstract: 12 nunoff plats were set up in mountain timber yards at four classes ofslope (e, g. 8,19, 24, 32), the fired position observations of the cultural land ofChinese fir had been continued for 4 years after control burning. The laws ofseasonal and annual changes in water,soil and nutrient losses of the forest landwere analysed from the control burning to canopy closure of Chinese fir cu-ltural land. The periods of soil and water losses were divided. The relation-ship between slope and loss was also analysed. The results indicated that run-off, soil and nutrient losses were most serious in the first year after controlburning, in which the amount of soil erosion was up to 24.81t/ha, then thelosses decreased yearly, and tend to[steadiness until the fourth year, which wassimilar to]that in the sites not to be burned. The common measure of culturaloperations aggrevated the amount of soil erosion. The authors suggest to adjustthe fashion and season of cultural operations, and adopt necessary biologicalmeasures.

Key words: Cultural land of Chinese fir, Control burning, Runoff plot, Runoff rate, Soil erosion, Soil and water losses